650.75-N4U
035-14370-000
26
Unitary Products Group
if allowed by local code. Follow the instructions with the coil
for trapping the drain.
SAFETY CONTROLS
Control Circuit Fuse:A 3 amp. fuse is provided to protect
the 24 volt transformer from overload caused by control cir-
cuit wiring errors. This is an ATO 3, automotive type fuse and
is located in the unit wiring harness between the control
transformer and the furnace control.
Blower Door Safety Switch:This unit is equipped with an
Electrical Interlock Switch mounted in the blower compart-
ment. This switch interrupts all power at the unit when the
panel covering the blower compartment is removed.
Electrical supply to this unit is dependent upon the panel that
covers the blower compartment being in place and properly
positioned.
Rollout Switch Controls:This control is mounted on the
burner box assembly. If the temperature in the burner com-
partment exceeds its set point, the igniter control and the gas
valve are de-energized. The operation of this control indi-
cates a malfunction in the combustion air blower, heat
exchanger or a blocked vent pipe connection. Corrective
action is required. This is a manual reset control and must be
reset before operation can continue.
Pressure Switches:This furnace is supplied with pressure
switches which monitor the flow through the combustion air/
vent piping system. These switches de-energize the ignition
FIGURE 34 : HORIZONTAL APPLICATION CONDENSATE DRAIN CONNECTION (MODELS P*DH / FG9-DH /
G9T-DH)
1
2
3
R I G H T A I R F L O W
( I N D U C E R H I G H )
A
B
C
1 - C O N D E N S A T E P A N T O T R A P
" A " D I M E N S I O N
2 - I N D U C E R B O T T O M T O T R A P
" B " D I M E N S I O N
3 - I N D U C E R O U T L E T T O T R A P
" C " D I M E N S I O N
H O S E
I D E N T .
N U M B E R S
5
4
D
4 - I N D U C E R O U T L E T T O T R A P
U S E A S P R O V I D E D
5 - C O N D E N S A T E P A N T O T R A P
" D " D I M E N S I O N
L E F T A I R F L O W
( I N D U C E R L O W )
H O S E
I D E N T .
N U M B E R S
Blower and burner must never be operated without
the blower panel in place.
Main power to the unit must still be interrupted at
the main power disconnect switch before any ser-
vice or repair work is to be done to the unit. Do not
rely upon the interlock switch as a main power dis-
connect.
